"In choosing the two teams for the matches at Edgbaston and Worcester, we were also mindful of the need to field a very strong England Lions side against Australia," Miller said.

"The inclusion of four bowlers with Test match experience and Ian Bell as captain demonstrates this."

Turning to the team to play Warwickshire, he added: "We have chosen two spinners in our side to face Warwickshire.

"But this does not necessarily mean that we will opt for the same balance in our bowling attack in the first Ashes Test. An extra pace bowler still remains an option for our starting line-up at Cardiff."

Miller said that as the selectors wanted to give all those playing in the two 'trial' matches every chance to press their claims for a Test place, England would now announce their squad for the Ashes opener on Sunday, July 5 - 24 hours later than originally planned.

The first Ashes Test is due to start in Cardiff on July 8.

Australia won the last Ashes series against England 5-0 in Australia in 2006-07.

Former captain Michael Vaughan was left out Monday of England's 16-man Ashes training camp squad.

Vaughan has not played for England since resigning as captain following last year's third Test against South Africa at Edgbaston, although he has often stressed how he he wants to play in the upcoming Ashes.

So far this season Vaughan, England's 2005 Ashes-winning captain, has done little for Yorkshire to press his claims for a Test recall, scoring only 159 first-class runs at an average of 19.88 in six matches.

Fast bowler Stephen Harmison, who also played in the 2005 series, was likewise omitted from the squad.

Instead his Durham colleague Graham Onions, who made his Test debut in the recent series win over the West Indies was included as was Ryan Sidebottom along with felloq quicks James Anderson and Stuart Broad.

All-rounder Andrew Flintoff, England's star of the 2005 Ashes, and Sidebottom were both recalled following injury. Tim Bresnan was included as seam-bowling cover for Flintoff.

"Michael Vaughan will, of course, be disappointed not to have been included," said England national selector Geoff Miller.

"But I met with Michael recently and he understands that he needs to make runs consistently in County cricket if he is to force his way back into the squad," the former England off-spinner added.

"The pre-Ashes camp is designed to give Andy Flower and the rest of the management team an opportunity to meet with the players ahead of their series and begin their preparations in earnest," Miller explained.

"We will continue to consider players outside the 16 chosen for the camp and will closely monitor performances in domestic cricket as the international season progresses. The door has not been closed on any player at this stage."

England also announced Monday the team to play Warwickshire in a three-day warm-up match at Edgbaston starting on July 1 and the Lions or A side that plays Australia in a four-day match which begins on the same day.

Harmison was included in the Lions side to play Australia, where the hosts will be captained by batsman Ian Bell, who is currently being kept out of the Test side by Ravi Bopara.